A cut-down version of this one won second place in its category in this year's Obfuscated Perl Contest. But I'm a little bummed because the first-place winner is actually a lot easier to understand. 

@P=split//,".URRUU\c8R";@d=split//,"\nrekcah xinU / lreP rehtona tsuJ"
+;sub p{
@p{"r$p","u$p"}=(P,P);pipe"r$p","u$p";++$p;($q*=2)+=$f=!fork;map{$P=$P
+[$f|ord
($p{$_})&6];$p{$_}=/ ^$P/ix?$P:close$_}keys%p}p;p;p;p;p;map{$p{$_}=~/^
+[P.]/&&
close$_}%p;wait until$?;map{/^r/&&<$_>}%p;$_=$d[$q];sleep rand(2)if/\S
+/;print

[download]

Hints are available from my web site. I will post the solution there at the beginning of December.

In reply to YAJAPH by Dominus

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